Flush push-button switch for electric circuits



MALCOLM H. BAKER, DECD. MARIE H. BAKER, ADMINISTRATRIX.

FLUSH PUSH BUTTON SWITCH FOR ELECTRIC CIRCUITS- APPLICATION FILED NOV. 8.1915. RENEWED APR. 14. 1919. I 1,328,481. Patented Jan. 20,1920.

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MALCOLM H. BAKER, or BRAIINTFIEE, IJLQSSACHUSETTS; Mar-am H. satanic, shimme- TRATBIX 0F sari) MALcoLr/r Z-I. nauuianncuasnn, assrou'oia TO KENNETH w. cnosnY, TRUSTEE, or nosrou, MasseCHUsnr'rs. I e

specification oi Letters Patent. I

PUSH-BUTTON S'WZTCH F03 ELECTRIC CIRCUITS.

Patented he. cameo.

Application aiea'nwe ber s, 1e15, Serial No. team. nemwea A ril 14, rate. serial No. 290,087.

To all whomkit may concern:

Be it known that I, MALCOLM H. BAKER, a citizen of the United States, and a resident of Braintree, in the county of Norfolk and Commonwealth of Massachusetts, have invented certain new and useful lmprove My invention relates broadly to switches of the type adapted to be operatedby alternate'ly pushing interconnected thumb huttons and wherein thermodynamically controlled means ar embodied to retain the switch controlled circuit closed a brief predetermined interval of. time afterthe con trolling button adapted to open the switch controlled circuit has been actuated.

i discussed in detail the many a vantages derived from such a switch when used in con neotion with electric lights, and have broadly and specifically claimed my invention as ap-' plied to various: classes of switches, and in' i the present application I specifically show i it as applied to apush button. type of switch h utilizing. separate cpptrol buttons to close and to cause opening of the switch. 1

I have illustrated my invention in the annexed drawings, in which Figure 1 is a sectional view of my improved switch taken I in section on line A- -A of Fig. 2. Fig. 2, is a front elevation, and Fig. 3 a section on line 'B .B of Fig. 2, the controlling push buttons being-omitted for clearness inthese three figures.

line DD of Fig. .1. Fig. 6 is a section on I of the electrical-connections of the switch.

In the drawings, '1 is the porcelain recep- 4 tacle containing the switchmechanism, andspectively. These buttons are pivoted re- 2, 3, the closing and opening buttons respectively .to opposite ends of alever 4 tulcrumed at a shaft 5 carried in alorackct 6 at ached to the container 1. Theioutton 2- v Fig. 4' is a section on line CC of Fig. 2, and Fig. -5 is a section on is hollow and contains a coiled spring 7 pressing against the stud 8 which is pivoted to the shaft or lever 4. v The button 3 is a simple solid button. The bracket 6 also carries a shaft 9 which passes through a slot 10 in the lever 4. This lever 4 has two spurs ments in Flush Push-Button Switches for;- Electric Circuits, of which the following is adapted to engage, at opposite limits of its motion with a spring detent 11, the said spurs appearing at 12, 13. Said lever 4 also has a projection 14 which is straddled by the ends of a coiled spring 15 wound about the shaft 9. The shaft 5, cat the lever 4, carries insulated contact clips 16 adapted to engage stationary blades 17 mounted upon the container Y1.

The container-1 carries a bracket 18 having a hinged detent arm 19 notched to engage an end 20 of the lever 4 and also shaped. to provide a cam surface 21 adapted to bear against the inner end of the button. 2. spring 22, mounted upon the bracket 18, acts to pressthe arm 19 against the end 20, I

The main contacts of the switch, hereshown as a single pole structure, appear at 23, 24, and engage blades 25, 26, stationary upon the container 1 through holding brackets '27, 28,said brackets carrying binding post screws 29, 30, adapted'to receive the line and load wiresof the circuit. The

main contacts are mounted upon and :insulated troma cam plate 31 having spurs 32,

33, engaging the endsof the spring detent' 11-.

The cam plate 31 also has an extene sion 34 ada'ptedto limit the swing ofsaid This cam plate 31is fixedly mounted upon the shaft 9 which also carries a second cam a: resistance winding 37 suitably insulated therefrom. This thermostat is mounted to the. container 1 by means of the bracket 6.

Operation is as follows: When the outton 2 1S pushed to close the switch 'it compresses the spring .7, releases the detent arm 19 and then swings the'lever 4 whereby the main contacts 23, 24, 25, and-26' are closed, with 'plate byengagement with the bracket 6.. V I

a marked snap due to the action of. the .springdetent 11. The heating winding 37 -of the thermostat 36 is inoperative since said winding is short circuited by the conmit currentto theload. To open the circuit tacting of the members 16, 17. The switch now operatesiii the normal manner to transthe button a is pushed. This swings back I the spring detent 11 until the end 20 of.

the lever 4: agalnst' the'yielding action of ing 37 solely in series with the load. The

thermostat is now heated, bends and releases the cam 35 which permits the main contacts to besnapped open under the actionof the spring The position of parts illustrated in the drawings is that assumed after the opemng ,button has been pushed, before the main con- :tacts have opened, and

while the thermostat isheating, y I

The time element elapsing between the pushing of the opening button and the actual opening of the switch'is of course the time required to heat to operation the thermostat, and it is evident that this time may be varied in many ways, such as altering the amount or size of wire on the thermostat, etc.

While I have illustrated a bi-metallic thermostat as the time'elementto delay the opening of the switch, itis perfectly evident that any suitable or equivalent form of' thermo-dynamic device may be employed.

Without, therefore, limiting myself to the precise embodiment of my invention herein shown,-what I claim is,

'1. In an electric circuit switch having a pivoted contact member arranged for rocking movement and manual controlling means to cause rocking of the same to close and to open the switch, in combination automatic switch opening mechanism comprising a detent and controlling thermostattherefor-pm sitione when the said thermostat is thermally deenergized to prevent the switch opening movement of said rocking member, rockmg driving means for said member and having 'a resilientconnection therewith, a-

detent device to 'hold said driving means whenmbved toa position to'put a switch opening tension on said member, a normally inoperative electric heater "for the thermostat, and means, controlled by said driving means. 1n sald last mentioned position thereof, and adapted to establish said heater in J operable'relation to the switch controlled at I pivoted contact member arranged for rockcircuit.

'2. In an electric -circi1it switch having a i movementand manual controlling means to causerocklngtof the same to close and toiopen the switch in -combination, ailtoa detent and .controlling thermostat therefor matic switch openingmechanism comprising positioned when the said thermostat is thermally de'elnergized to prevent the switch opening movement of the said rocking member,roclnngdr1v1 ng means for said member te m and having a resilient connection therewith, a detent device to hold said driving means when moved to a position to put a switch opening tension on said member, a normally inoperative electric heater for the thermostat, and means controlled by said driving means in said last mentioned position thereof and adapted to establish said heater in operable relation to the switch controlled circuit; together with means, controlled by the reverse movement of said driving means,

to close the switch.

3. In an electric circuit switch having a pivoted contact member arranged for rock- I ingmovement and manual controlling means to cause rocking of same to close'and to open the switch in combination, automatic switch opening mechanism comprising a detent and controlling thermostat therefor positioned when the said thermostat is thermally deenergized to prevent said rocking member to move to open the switch, rocking driving means for said member and having a resilient connection therewith, a detent device to holdsaid driving means when moved to a position to put a switch opening tension on said member, 'a normally inoperative electric heater for the thermostat, and means controlled by the said driving means in said last mentioned positionthereof and adapted to'establish said heater in operable relation to the electric circuit; together with means,

, controlled by the'reverse movement of said driving means to close the switch and to maintain it closed, independently of said thermostatic detent, for normal operation.

4. In an electric circuit switch, in combination, a pivoted rocking contact member, rocking driving means therefor having manual controlling means, a resilient connection between said driving means and -said mem-. ber, positive detent devices for said member governed by the movement of said driving means, a thermostatically controlled detent arranged to lock said member to maintain e the switch closed when said member is ten- .sioned for switch opening by movement rela- "tive thereto of said rocking driving means and adapted when energized to release said member to open the switch, auxiliary detent v means to lock said driving means in position to openthe switch when the switch is maintained closedby said thermostatic detent, an electric heater for the thermostat, and circuit connections to connect said heater .operatively to the electric circuit 7 when said driving means are moved toa position to cause opening of .the switch. w

' 5. In an' electric circuit switch,- in combination, a pivoted rocking contact member,

rocking driving means therefor having'mam ual controllingmeans, a resilient connection "between said driving means and said member, positive detent devices for said member governed by the movement of said-"driv ng 'tion to open the means, a thermostatically controlled detent arranged to lock said member to maintain the switch closed when said member is tensioned for switch opening by movement relative thereto of said rocking driving means and adapted, when energized, to release said member to open the switch, auxiliary detent means to lock said driving means in posiswitch when said switch is maintained closed by the said thermostatic detent, an electric heater arranged-in series with the switch circuit and adapted when energized to operate thethermostat and a shunt circuit around said heater arranged to be normally closed while the switch is closed and further arranged to be opened when the driving means are moved to a position to cause opening of the switch.

6. An electric switch embodying an oscil- -lator v contact member; an oscillatory actuator element mounted for swinging displacement relative to said member; a spring and detent connection between said member and said element whereby swinging displacement of said element relative to said memberin either direction of the latters oscillation causes quick follow-up movements of said member in the'corresponding direction respectively to make and to break a circuit; a separate'detent arranged to preventsaid follow-up movement of said member from its circuit making position when said element is displaced therefrom; means to hold said element so displaced whereby said member is tensioned for circuit breaking movement;

and normally inactive, slow-acting instrumentalities arranged to be operatively energized by said displacement of said element, and thereby rendered operative to free said separate detent after a predetermined interval of time.

Signed at Boston, in the county of Suf folk and Commonwealth of Massachusetts, this second day of November, 1915.

V MALCOLM H. BAKER. Witnesses: y

R. D. SMITH, Y SmvIo AMOBOSO. 

